Satellite Pose Estimation via Single Perspective Circle and Line

Pose estimation is vital for space robot to capture satellite. Dual poses including center position and normal direction can be obtained from a single perspective view of a radius-known circle such as docking ring of the satellite. To solve the duality and recover the roll angle, this paper presents here a new method called perspective circle and line (PCL), which is based on the perspective view of a single circle and line. First of all, the dual center positions and normal directions are recovered with the circle and the image. Then, the line is utilized to recover the roll angle of the circle analytically. By reprojecting a random point on the line to the image and verifying whether the projection lies on the image line, the false pose of the object is identified. Simulation and physical experiments show that the position and orientation of the circle can be recovered. But in practice they are affected by the accuracy of camera calibration and feature extraction. As a whole, PCL is robust to noise in pose estimation, especially in recovering the orientation.